A contactless communication device such as that defined by Standards ISO 14443, ISO 1593 or ISO 18000-X, for example, usually comprises an inductive antenna formed by an electrical conductor which forms one or more loops and is connected to an integrated circuit which causes the voltage and/or load across the terminals of the antenna to vary in order to generate an amplitude-modulated or phase-modulated magnetic field. Communication can thus be established with another device of this type located within the communication range of the first device because of the electromotive force produced between the antennas.
Integrating contactless communication technology in a mobile device such as, for instance, a mobile phone, a smart phone or a digital personal assistant, makes it possible to use the device for other purposes, e.g. as a “contactless card” (payment, computer ticketing, couponing, access control, etc.) or “contactless card reader” (reading information contained in RFID labels located in the street, on merchandise or elsewhere).
However, contactless reading usually requires a minimum of 2 W in order to communicate in the 13.56 MHz frequency band using contactless cards which comply with Standard ISO 14443 or Standard ISO 15693 or RFID labels which meet Standard ISO 18000-X.
The power required therefore makes integrating such a function in a mobile device problematic. In fact, implementation entails a reduction in the battery life of the mobile device or involves oversizing the device's energy source in order to compensate for the excess power consumption associated with the contactless reader function.